1. Technical Field
The present invention relates to a screen, and particularly to a technology of a screen that reflects light projected from a projector.
2. Related Art
A front-projection projector is used in combination with a reflective screen that projects projection light. A reflective screen can relatively easily provide a high-brightness, high-contrast image in a dark-room environment. On the other hand, in a conference room, a room in a general household, and other bright-room environments, the fact that the screen reflects not only image light but also ambient light causes the portion that should be displayed in black to be whitish black in some cases. This phenomenon is called black floating. It is therefore a challenge to provide a high-brightness, high-contrast image on a reflective screen even in bright-room environments. For example, JP-A-2006-215162 proposes a technology in which convex portions having a unit shape are regularly arranged and a reflective portion is provided on each of the unit-shaped portions but only on the portion on which projection light is incident.
In the technology described above, not only is a certain amount of the projection light that is obliquely incident on the screen reflected in the direction of the normal to the screen, but also a large amount of the projection light travels in the direction that forms the same angle as the angle that the incident light and the normal to the screen form (the direction in which the incident light specularly reflected off the screen travels). When the amount of light that travels obliquely to the normal to the screen increases, a viewer in front of the screen disadvantageously views a dim image. As described above, the related art is problematic in that the light unlikely travels in an efficient manner with an appropriate angular distribution in an area in front of the screen.